Generally, a submarine has a forecastle and a poop and further has a crew room formed at the interior thereof so as to hold passengers thereinto. So as to allow the passengers to get into the crew room, furthermore, a hatch is provided on the upper portion of the submarine. Typically, the submarine has been used for underwater infiltration or vehicle.
With the development of leisure culture, recently, the submarine is also used for underwater viewing, but since the crew room where passengers get into is closed from the outside, simple visual viewing is provided to the submarine for underwater viewing, thus making a level of leisure experience substantially low.
Further, the hatch is disposed on the upper portion of the submarine and necessarily fixed to the submarine, so that in the state where the passengers get into the submarine their visual viewing space is restricted to provide a substantially low level of leisure experience.
Accordingly, there is a definite need for the development of a manned submarine capable of providing a high level of underwater viewing and experience to passengers.